Mr. Blackwall's Descriptions of new Species of Spiders. 627 



14. Theridion albens. Albidum ; ovalibus 2 parvis obliquis e lineis tenuibus 

 nigris efFormatis prope abdominis medium ; cephalo-thorace fascia ob- 

 scura mediana ; oculis in anteriore cephalo-thoracis parte positis, inter- 

 mediis quadram referentibus ; labio triangulari acuto. 



Length of the female ^th of an inch ; length of cephalo-thorax -^ ; breadth 

 -g^ ; breadth of abdomen -g^ ; length of an anterior leg -j^ ; length of a 

 leg of the third pair xs. 



Cephalo-thorax glossy, compressed before, convex above, with a slight inden- 

 tation in the medial line of the posterior region. Mandibles small, conical, 

 vertical. Maxillae slender, obliquely truncated at the extremity, on the 

 outer side, and inclined tovi^ards the lip, which is triangular, and pointed 

 at the apex. Sternum heart-shaped. First pair of legs the longest, tlien 

 the fourth, which a little exceeds the second in length, third pair the 

 shortest. Tarsi terminated by three claws ; the two superior ones are 

 curved and pectinated, and the inferior one is inflected near its base. 

 The palpi have a curved claw at their extremity. Abdomen thinly co- 

 vered with hairs, very convex above, projecting greatly over the base of 

 the cephalo-thorax. The general colour of this spider is whitish, but a 

 small, oblique oval, formed by a fine, black line, occurs near the middle 

 of the upper part of the abdomen, on each side of the medial line ; the 

 sexual organs also are black, and an obscure band of a darkish hue ex- 

 tends along the middle of the cephalo-thorax. Eyes seated on black spots 

 on the anterior part of the cephalo-thorax ; the four intermediate ones 

 form a square ; the other four are disposed in pairs on the sides of the 

 square, the eyes constituting each pair being contiguous and placed ob- 

 liquely on a slight protuberance. 



The minute spider from which the foregoing description was made was dis- 

 covered in July 1837, among strawberry plants growing in my father's garden 

 at Hendre House, near Llanrwst. 



15. Theridion callens. Cephalo-thorace pallid^ flavescenti-brunneo, lateribus 

 maculisque pluribus triangularibus quarum maxima centrali nigris ; ocu- 

 lis in anteriore cephalo-thoracis parte, intermediis quadram referentibus, 

 seriei anterioris in tuberculo positis ; mandibulis saturate brunneis ; 



VOL. XVIII. 4 N 



